Data handling system



March 30, 1965 c. R. FISHER, JR

DATA HANDLING SYSTEM 3 Sheets-Sheet 1 Original Filed Jan. 18, 1957TEANSM/TTER TRANSMITT/NG Q/ T MTM, /E HM 2 SP4 Ww E ...m 0 W T 0 V u..NH A/ Mlroo ME M 0E N .k D C om ...Am n a A Mm M w N .mi 2/ Z foe) Mardi30, 1955 c. R. FISHER, JR 3,176,287

DATA HANDLING SYSTEM Original Filedf Jan. 18, 1957 5 Sheets-Sheet 2 Z/ZZMAR/(s2 caNT/zol.

A/JD REG/irez Decanen T/aAMsM/TT/A/q coMMu r4 T02 March 30, 1965 c. R.FISHER, JR 3,176,287

DATA HANDLING SYSTEM Original Filed Jan. 1Q, 1957 3 Sheets-Sheet 3United States Patent C) 3,l76,287 DATA HANDLNG SYSTEM Charles R. Fisher,lr., Pittsford, NPY., assigner to General Dynamics Corporation,Rochester, NX., a corporation of Delaware Original application lan. 18,1957, Ser. No. 634,973, now Patent No. 2,976,347, dated Mar. 21, 1961.Divided and this application .lnly 28, 1960, Ser. No. 45,906

17 Claims. (Cl. 340-345) This invention relates to a data handlingsystem and, more particularly, to new and improved means for reproducingand transmitting coded signals. This application is a division of acopending application of Charles R. Fisher et al., Serial No. 634,973,led January 1S, 1957, now Patent No. 2,976,347, issued March 2l, 1961.

In existing data handling systems of the type used in a telegraphnetwork, lengths of a record medium, such as paper tape, are used inreperforating equipment to provide intermediate data storage atswitching points or between data originating and terminating oiiices.The use of an expandable storage medium, such as a perforated tape, issomewhat costly from the viewpoints of material cost and handling timeand usually requires the provision of an essentially mechanicalmechanism, such as a perforator. Because of the high operating speedsutilized, these mechanical components require precision construction,are diiicult to maintain without skilled personnel, and involve a ratherlarge capital expenditure. In addition, it Often is not possible tofully realize either the high speed operation or the reduction ofinstallation space aiiorded by electronic techniques when mechanicallinks are interposed in the system.

Accordingly, one object of the present invention is to provide a new andimproved data handling system.

Another object is to provide a data handling system including areuseable storage medium.

A further object is the provision of a system of the type describedabove having new and improved data transmitting means.

Another object is to provide an improved commutator or distributorconstruction.

Another object is to provide means controlled by stored and coded dataentries for transmitting signals representing the stored data entries.

A further object is to provide a data handling system including meansfor storing a coded entry and means n controlled by the storing meansfor transmitting certain stored entries and for decoding andtransmitting other stored entries.

Another object is to provide a transmitting commutator including a marksignal channel and a space signal channel and means including aplurality of gating means controlled by a stored coded entry fortransmitting signals over said mark and space signal channelscorresponding to the stored entry.

Another 'object is to provide a transmitting commutator including newand improved means for concurrently reproducing the bits of a codedentry from a record and for sequentially transmitting signalscorresponding to the concurrently reproduced bits of the entry.V

Another 'object is to provide a transmitting commutator in which aplurality of bistable bit storage units control both switching means forextending a connection to a data receiver and means for transmittingsignals corresponding to a data entry stored in the bit storage units.

A further object is to provide a transmitting cornmutator in which aplurality of bistable bit storage units for storing a coded data entrycontrol a gating net- F work that both decodes stored entries andtransmit signals representing stored entries.

Gti

ice

In accordance with these and many other objects, an embodiment of theinvention comprises a data handling system including transmitting meansfor supplying groups of serially transmitted signals representing codeddata entries, such as those provided in Baudot code. A receivingcommutator controlled by the serially transmitted signals operates arecorder to store each coded data entry in parallel form on a magneticmember, such as an endless length of magnetic lrn or tape.

The parallel data entries stored on the magnetic lm are reproduced by atransmitter spaced from the recorder, and the reproduced signals areforwarded from the transmitter to a transmitting commutator in which theconcurrently reproduced bits of the coded parallel data entry are storedin a corresponding number of bistable bit storage units. Thetransmitting commutator includes a first gating network controlled bythe bistable storage units for recognizing certain data entries that areto be forwarded from the transmitting commutator to a marker control andregister decoder. These data entries are decoded in this unit andsuppled to switching equipment that extends a signaling path from thetransmitting commutator to a selected data receiver. When the signalingpath has been established, the parallel entries subsequently transferredfrom the transmitter to the transmitting commutator are stored in thebistable bit storage units as parallel entries. These entries are thenconverted into corresponding groups of serially transmitted codedsignals under the control of a second gating arrangement which iscontrolled by the bistable bit storage units and which is driven by acounting circuit.

Many other 'objects and advantages of the present invention will becomeapparent from considering the following detailed description inconjunction with the drawings in which:

FIG. l is a block diagram of a data handling and transmitting systemembodying the present invention;

FIGS. 2-4 are a schematic circuit diagram of a transmitting commutatorincluded in the system shown in FIG. l; and

FIG. 5 is a block diagram indicating the manner in which FIGS. 2-4 arepositioned adjacent each other to form a complete circuit diagram of thetransmitting commutator. For convenience, each of the conductorsinterconnecting the various iigures has been given an individualreference numeral which appears on each figure on which that individualconductor appears.

Referring now more speciiically to FIG. 1 of the drawings, therein isshown a data handling system, indicated generally as 100, which embodiesthe present invention and which can comprise a telegraph switchingsystem of the type described in detail in the above identified Fisher etal. application. To illustrate the relationship between the circuits inthe present application and the Fisher et al. application, the samereference numbers have been used in both applications wherever possible.In general, the system 10d includes transmitting equipment 1&2 at alocal or remote point for transmitting successive Baudot codecombinations over a signaling line to a receiving commutator 134. Thereceiving commutator controls a recorder 136 to record the seriallyreceived code combinations as parallel entries on an endless loop ofmagnetic lm or tape 137. The recorder 136 includes ve transducing orrecording heads corresponding to the five information or mark and spacebits in the Baudot code, and these tive heads are dis-k The receivingcommutator 134 controls thel U37 l n l Y Y Yaligned permutation 'ofmagneti'z'ed l'or Ynonmagne conditions on the five channels of the film1377.

Y When .the data stored on the magnetic film "137 is to be"re'produ`ced,a transmitter 138isfplaced in operation toadvancesthe magneticIfilm"1.a7'step'bystep'.Y As Veach code" combination or-y data entry isadvancedfpastffive reproducing'orI transducing'headsdisposed adjacentthe five'channelsor'the film, the transmitter 13S-concurrentlyyreproduces'the bits of ythe recorded'codel combination and transmitsthese bits to atr'ansrriitting` cornmutator 214 which'each of the bitsis 'stored-in', one ofy live bistable bit storage units. Thetransmitting conimutator'includes means for `detecting certain lcodedentries and for forwardingv thesef entries to -a marker control andregister v deicoder2.3t),' .24,0y in which the data entry istranslated'intocontrolsignalsfor selectively operating switching equipment218;'*219ft0'extend an output signaling path foni'tlietransmittingcommutator l2`14to a data receiver 104i' When thesignaling'path has beenx completed; the

vtransmitting communtator 21d-'is controlled bytheftrans-Y mitter 138110transmitv subsequentlyk Yreproduced data entriesthroughjthe switchingequipment to 'the "data Vreceiver in the form ofa series of groups ofmark and space pulses representing" `the information previouslythetrnagnetic tilm'137 by the recorder 136.`

The iive binary storage unitsV provided in the transmitting commutator214 comprisesi'ive pairspfV controlled conageunitsthe'output electrodesof vthe controlled conduc- Ystoredv on and space signals formingeachBaudot code 'combina-V tion, the-*recorder 136 incldes five magnetictransducing or recordingfheads 921-925 that are disposedadjacenttransversely spaced 'portions of the magnetic member 137 to delineseparate data receiving channels. Although the tranducing headsr 921-925are shownin transversely Y aligned positions;v these heads'vcan Ibe'disposed in any suitable staggered arrangement. vThe recorder 136/- alsoincludes a driver mechanism' for' advancing the magnetic 'following eachrecording operation.

. conductor.

sponsive to the potentialfexisting on arcommon signaling Thecircuitse'in theV receiving commutator" V134i are such that-thewindin'gof the headr921 is ener-V gized tomagnetize the portionof themagnetic lrn 137 ductionldevices `connected ltorhave `twoalternate''stable .l conductive'states. To provide means forv decodingcer-*f1 v tain onesjof the coded data entries stored in thefbit stor'tiondevices"in the'bitistorageunits are connected to'V a v Y.

first gating"'matrix comprising apluralityV of Aneon diodes connected`betvveena p'ulse sourcej and a number ofY der tecting means.` If `apredetermined coded combinationv isstored'in thel bitl storage units; aread pulse applied toA `Baudot codedrentriesin which va magnetized arearepre-l disposed belowl its gap if:V the rst received vinformation .ibit is avmarkplllse.v Thewindingof'thefhead'921 is not Aenergized if theiirstinormationbitis a space pulse. .The

remaining'heads9224925 are energized insequence soy that the head 925'records the mark or space-signal form. ingthe last information vvbit inthe Bandot'code combina-V tion;Y Accordingly, the'magnetic iilr'n 137 isprovided with Ysuccessive parallel patterns' of magnetized andnommagnetized incrementalareas'lcorresponding to successive sents arecorded mark signal.v

The transmitter 138 includes iivereproducingor'magnetictransducing'heads'9314935 `disposed'adjacent the theinput ofthe seriesconnected'neondiodesV is Ytrans-V ticular entryfhasy been 4stored. If the coded entryis one,

for instance,` that indicates Ythat the following entries are fswitching codes', the following entries stored in the bistable circuitsvare forwarded'togthe marker control Vand registerY decoder 2730, 240 inwhich .they are decoded tor-'provide signals for operatingthe'switchingequipment 218; 219.

To' control the transmission of the parallel coded entries storedj inthe bit `storage unitfs` the transmitting comv 1nut`atorf214' includesl`a vmarkI signal' channel and a space rnitt'ed over given pathrthroughthese' diodesV to oneof f the detecting means to provide an indicationthat a parfv five transversely spaced and longitudinally extendingchannels :infwhich d atais recorded bythe transdcing heads '92,1--92'51`The ltransducing heads 931-935 are connected to vthe input offafive'channel amplifying means 920, the- Youtputof whichisiconnected'tothe'ive bit storage units in' thejtransmittingcommutator'i214." 'To provide means for advancing themagnetic member 137past the heads i 931-935,'the transmitter 138'inc'1udes a drivemechanism signal channel which'. .arev connectedv by pairsv of neon*ydiode: 'gates'toa counting 'chain'dr'iven by amultivibrator.

These pairs of neon Y* diodel 'gates "aref connected f to cor- 97314935-and 97215925that, theV signals recorded on the t magnetic member'137 bythe'fheadsj921-'925 are'moved resp'ondingsonesi ofthe bit storageunitsfand are selectiven' 1y enabled' byrthev condnctivepatternsexisting '.therein. When the countingcircuit is Yplaced'fin'operationeach;ofv thevpairsv of gates' isrpulseidtfand'the enabled 'one`of each" palireof these gates'transmitsztheapplied pulsefove'rthe*mark'forispace signaling channe'ljto a'bistable''or nip-flop'VVoutput'circuit.'Y This bistable` circuit, which' is'connected i ofthetype shownY in det-ail in the'abovelidentiiied Fishervr et.: aL`application.v i This drive Vmechanism includes a "sprocketwheel;whichlgengagesl the sprocketf'holes yin the magnetic'member137'and Which-iis driven by the releasev orfva solenoid 91). The drivemechanism in the transmitter` 138 is fso positioned relative tothetransducingheads ;orswept past thegaps-in the heads` 931-935 when vthevoltages appear atA vdriveme'ans' isjoperated The "existence of amagnetized` area representing Aa recordedmark signal induces a voltageinthe windings ofthe'heads.931+935',V andthese induced. the.; outputs'ffthe 4'amplifying meansI 92) as 'positive-goingpulses.'V

fo the outpursignalingiine or, channel; it operates be;Y i

tween-alternate marl".I and` Vspace conditionsV accordance;

W'ith'ithe .permutation lof signals ."supplired'fonv the v niark! and jspace channels' and controlsthe l application of Vva *core* Therecorder136 and tlief transmitter 138 (FIG. 2)'v cani comprise any :suitablemagneticV data storinglappara'tus,z such i as Vthose utilizingVamagnetic drum or-fta'pe Vvas `'aV record elementi.:- Ho'wever, therecorder'136 and/'the j v transmitter 1=38--preferab1y-includev anapparatusof the l. 70

type shown and describedin detail intheY above identifiedrespondingpatternofv voltages toV the output `'signaling lis'her etapplication. `illustrated therein, Ythe magnetic .member` 137 "comprisesan` endless lengthfor closed'loopof aflexible magnetic vfilmV havingalrlongi-Y, 'tudinally extending row ofllsp'rocket holes'adjacente'ach`VYThe operation'of the transmitter ISSaDdthe/transmitting conimutator214V to retransmit l the information stored Von the ir'iagne'tic'`lmv137g`by the'recorderf'jis initiated'` under the', *control of'contacts'lthat are actuated to opened Vor closed conditionsv iniaccorda-nceywith the length ofy .the .supplyfloopl offriilm vdisposedvbetween the recording Y"heads f 921-9`2f5and. fthdireproducingVl'ie'ads' v'931-935. Y When 'an adequate' supply-'loop' of'E film 137A`having Vdata storedl Vthereon isV providedbetween-the recorder 13.61

and the' tran'smitterr138gj anoperati'ng ycircuit -is completed for 'a'start `relay 1500' inV the transmitting'-r commutator 214. .V'Iheoperation Voffthepstfart n'rela'yltl closes apairl,of.contacts.1501toconnect`Bl- .potential across Va voltageYdividerconnected ytothe control electrode of a start pulse ma@ isiafvid .einer Y 'gasesus .discharge-'imma Y1511;` i512;v 1513, 1514'y jan/d51515, representing the" five bits of; the ,'Baudot "codeg' 1 acountingV chainincluding a" plurality, .of

and a stop tube 1516. These tubes are connected to form a seven elementcounting chain. The control electrodes of these tubes are capacitivelycoupled to the output of a continuously operative multivibrator 1455.Accordingly, following the closure of the contacts 15191 to provide anenabling bias for the tube 1519, the first pulse supplied by themultivibraotr 14d@ is coupled through a condenser 1566 to nre the tube1510. Firing this tube provides a potential drop in its cathode circuitto supply an enabling bias for the second tube 1511 in the countingchain. 1n a similar manner, the pulses applied by the multivibrator14110 to thek counting chain including the tubes 1510- 1516 sequentiallyrenders each of these tubes conductive.

Since the data stored on the magnetic lm 157 by the heads 92.1-925 isspaced from the reproducing heads 931- 955, the magnetic film 137 mustbe advanced before combinational code data can be reproduced andtransmitted to the transmitting commutator 214. Accordingly, atransistorized drive circuit for the motor magnet or solenoid 91) in thetransmitter 138 is provided which is controlled by the stop tube 1516 inthe transmitting commutator 214. More specifically, the base electrodeof a transistor 1529 is normally connected to negative battery through aportion of the cathode resistance of the stop tube 1515 to maintain thebase elecrode negative with respect to the grounded emitter ot thetransistor 162i), thereby holding this transistor in a conductivecondition. However, when the tube 1515 is tired under the control of themultivibrator 146) and the preceding tube 1515 in the counting chain, apositive voltage drop is produced across the cathode resistance of thetube 1516 to render the base electrode of the transistor 1625 positivewith respect to its emitter so that this transistor is cut off. Thetermination of collector current liow through the transistor 1629 and aballast lamp 1522 applies a more negative bias to the base electrode ofa transistor 1521, the emitter electrode of which is supplied with afixed negative bias. The magnitude of the negative potential supplied tothe base electrode of the transistor 1621 is greater than that appliedto the emitter electrode so that the transistor 1621 now conducts toprovide a current liow through the operating winding of the motor magnet910.The energization of the motor magnet 510 opens a pair of interruptercontacs 911 so that B+ is removed from the counting tubes 1515-1516,thereby extinguishing these tubes. Extinguishing the tube 1516 returnsthe base electrode of the transistor 162@ to a negative potential sothat the transistor 1625 begins to conduct and conduction in thetransistor 1621 is terminated to release the motor magnet 9.1i?. Therelease of the motor magnet 915 closes the contacts 911 to again applyB+ potential to the gaseous discharge tubes in the transmittingcommutator 21d and also releases the step drive mechanism so that themagnetic tape 137 is advanced a single step relative to the reproducingheads 931-935.

This intermittent operation continues until such time as the iirst itemof information recorded on the magnetic iilm 137 has been advanced to aposition adjacent the transducing heads 931-935. The counting chain thenadvances through another cycle of operation in which the motor magnet91d is momentarily energized and released to sweep the first recordedcode combination past the transducing heads 931-935 so that theamplifier 925 selectively transmits positive impulses to thetransmitting commutator 214 in accordance with those of the tivechannels on the magnetic hlm 137 in which mark pulse information hasbeen recorded. This information is stored in live bistable circuits orbit storage units in the transmitting commutator 214.

More specifically, the transducing heads 951-935 control the storage ofinformation in a plurality of bistable circuits including pairs ofgaseous discharge devices 1520 and 1525, 153i) and 1535, 154i) and 1545,163th and 1,535, and 1641i and 1645, respectively. The storage in CIIthese bistable circuits is such that the space tubes 1525, 1535, 1545,1635 and 1645 are normally in a conductive condition representing aspace signal, and the associated mark tubes 1520, 1536, 1540, 1630 and164i! are selectively red in response to sensing recorded pulses in therelated channels on .the magnetic tape 137 representing mark signals. Asan example, assuming that a mark pulse Vis sensed by the transducinghead 931, a positive pulse is coupled through a condenser 1521 to thecontrol electrode of the mark tube 152i), which control electrode isprovided with an enabling bias by a voltage divider connected between B+and ground. The application of a positive pulse through the couplingcondenser 1521 lires the tube 1520 so that a positive voltage drop isproduced across a cathode resistor 1522. This positive voltage drop,together with the positive potential across a normally charge-:lcondenser 1523, elevates the cathode potential of the space tube 1525 sothat conduction in the normally conductive space tube 1525 no longer canbe maintained, and the tube 1525 is extinguished. When the tube 1525 isextinguished, the condenser 1523 charges to a voltage equal to the dropacross the cathode resistor 1522. in the cathode circuit of the marktube 152). ln a similar manner, and simultaneously with the operation ofthe first bistable circuit controlled by the transducing head 931, theremaining bit storage units are selectively transferred to markingconditions if pulses are sensed by the heads 932-935 on the relatedchannels of the magnetic film 137.

At the end of each cycle of operation of the counting chain, all of thebistable circuits are. restored to a spacing condition under the controlof the stop tube 151:5. Firing the tube 1516 couples a positive pulsethrough a capacitor 1541 to a plurality of blocking diodes associatedwith the control electrodes of the space tubes 1525, 1535, 1545, 1635and 1645. These diodes are similar to a neon lamp 1646 associated withthe control electrode of the space tube 1645. One side of all of theneon lamps is connected to ground through a resistor similar to aresistor 1547, and the other side of all of the neon lamps is connectedto a positive potential provided by a voltage divider including a pairof resistances 154-2 and 1643 connected between B+ and ground.Accordingly, when a positive pulse is coupled through the capacitor1541, all of the neon lamps break down and conduct the pulse through aplurality of coupling condenser-s, similar to a coupling condenser 1648,connected to the control electrodes of the space tubes. Since thecontrol electrodes of all of the space tubes are provided with a lixedenabling bias from related voltage dividers, these pulses render all ofthe space tubes 1525, 1535, 1545, 1535 and 1645 conductive. Renderingthese tubes conductive provides positive potential drops across theircathode resistors Whioh, together with the voltages across the cathodecoupling condensers connected to conductive mark tubes, is sufficient toelevate the cathode potential-s of the conductive ones of the mark tubes152i?, 1535, 154i?, 163i) and 164i) to a point at which conduction nolonger can be sustained. Accordingly, all of the conductive mark tubesin the transmitting commutator 2141 are extinguished in response totiring the stop tube 1515 in the counting chain.

In a telegraph switching system of the type described in detail in ltheabove identied Fisher et al. application, the item of information-stored on the magnetic film 137 at the beginning of each message is agroup of successive code combinations representing a letter shift, a tigre shift and a character E This group of codes controls the datahandling system to divert the following message material received fromthe transmitting equipment 152 to a special storage means (not shown)provided in the System. Thus, the first item of information reproducedfrom the magnetic film 137 by the transmitter 13S is a letter shift codecomprising mark pulses in all of the five channels of the magnetic tape137. Accordingto sweep this code combination past-the .transducing heads931-935, positive pulses are transmitted through the amplifier 920-tothe control electrodesof all of Vthe mark tubes 1520,- 1530, 1540,y.1630' and 1640, thereby renden' ing all of these tubes conductive andVextinguishing all lof f the space tubes 1525, 1535, 1545, 1635 and'1645.Since anumber of diiferent figure shift plus character codecombinations,such as `figure lshift E iigu'reshift G,. andV figure shift -YH, are`used for control'functions, the'transf mitting-commutator 214 includesa decoding circuit ar rangementvfory detectingand storing either` alettershift or a figure shift condition and for detecting certain othercharacter codes.- This decoding circuit arrangementis of fthe generaltype shown and described in United States Patent- Nos.`2,787,780 and2,787,781.

In general, the decoding circuit comprises series circuits of blockingdiodes, such fasV neon lamps, connected between pulse sources` anddetector tubes for permitting the pulse sources to operate -a selectedvone of the detector tubes only .when

a selected code combination is stored in the bistable circuits.V seriescircuit are selectively connected to the cathode circuits of each of thebistable circuits to receiveforward;`

or reverse biasing potentials in accordance with the storage of a spaceor a mark condition in the related bistable circuit.`

To accomplish this, the blocking diodesrin each To decode orrecognizethe letter shift code now stored Y in the bistable circuits, the nexttiring of the startl tube 1510 in theV counting chain forwards apositive pulse over a condenser 17676 to the control electrode o f agaseous dis,-V

charge prime tube.1675, the control electrode of Ywhich is provided witha xedenabling bias by. a voltage divider. Y

The ring'gof the tubev 1675 producesa negative-going pulse at the anodethereof which iscoupled through a condenser 1'6779 to the anodeof anormally conductive tube 1680, thereby extinguishing this tube. Apositive' potential drop is produced across a cathode resistor 16787'bytiring i the prime tube 1675, and this positive potential is supplied toa terminal v1677' which is connected to a plurality of terminals 1651',1661` 1666, and 1671'to provide an enabling bias for a plurality oftubes 1650, 1655; 1660, 1665 and 1670. i f

The sequential operation. Vofthe counting chainA inr-` cluding tubetubes 1511, 1512,.1513, 1514 and 151`5'con-'7y tinues, as describedabove, until thetube 1515 is'rendered conductive to produce apositive-going-fpulse that is coupledthrough a condenser 1551 to thecontrol electrode of f a letter shift drive tube l1550,A the controlelectrode vof willich is providedrwith. a/xed enablingbiasV bya voltagedivider. lThis pulse renders'thetube r1550!conductive` so that thepositive-going pulse appearing 'across it'spcathode 1 resistor 1552.iscoupled througha condenser 1553'to va blocking diode 1554 comprising aneon ,lamp Y, Thev Vright hand terminal of the'lamp 1554, `as'showninFlG. 3, is connected tofground through aresistor 1556 and aYYportion of `thecatihode resistance of the nonconductive spacetube'1525. The terminal'of theneon lamp y155,4 that is Vconnected tothecondenser: 1553 is supplied with va positive potential fromv the cathoderesistor V175,22jmof the conductive'mark tube 1520 through a vresistor1555. T hepotentialfapplied acrossthe-lamp1554 dueA tov thel conductivecondition ofvtheY mark tube 1520 Ais slightly below its Vionizingpotential iso thatV positive pulse'supplied through thecondenser-1533ionizesthe neonla'mpl 1,554 to couple the positive-'goingpulse to aY condenser 1557. Y Y f v Y Y In asimilar manner,

of other blocking diode`s,"similar to the'. neon lamp 1554',

due to the conductivecondition- 'A of the mark tube.1530,154051630and1640, a pluralitydrop across its cathode resistor 1652 which, when addedv to the voltage .across a cathode coupling condenserr1653,

f is suicientto extingui-shrrthe figurey shift tube 1655. Ac-

cordingly, the `transmission of the letter shift code to thetransmitting commutator 214 causes Ithe tiring of the letter jshift tube.1650 toy store vvthis information in the transmitting commutator 214. Yt

Referring backgto the ring of the tube 1515, which tube represents'thelast informationbit in the transmitted combinational code, the-firing ofthis tube also couples a positive pulseithroughl acondenser 1681 to thecontrol electrode of the tubev 1680, the controlelectrode of which isprovided with a fixed enabling bias'. by a voltage divider. This pulseres the tube 1680 to produce avnegative voltage swing ,which iscoupledthrough thecondenser 1679 to extinguish the prime tube 1675,thereby removingthe posi-l tiveenabling biasfromthe terminal 1677Vandthe controli V'electrodes connected thereto.' However, thisdoes notkchange theconductive condition of the discharge device 1`516'againreleasesthe motori magnet 910 so that the nextv code combination storedon'themagne'tic film 1r37"is moved past the transducing heads 9731-935to vtransmit mark pulses representing the figure shift code combinationto the control electrodes of onlyjthe tubes 1520, 1530, 1630 and 1640soastto render vthese tubes conductive-and V-to extinguish Vthe tubesv1525, Y1535, 1635 and'1645. Ac-v cordingly, the tubes'1520, 1530, 1545,1630 andv 1640 are now in conductive condition representing theligureshift codefcombination. 'I v When the nextv cycle, of operation of thecounting chain in the transmittng'commutator v214 is initiated followingf the storage of the figure shift code in the bistable circuits,

the prime tube 1675 is again rendered conductive to provide an enablingpotential for Vthe controlelectrodes Aof the tubes 1650 and 1655, amongothers,'and the tubevv 1680 I is again extinguished. When thelast codebit tube 1515 is again rendered conductive, a pulse is onceiagaintransmit` ted over the coupling condenser 1551 to tire the tube 1550.

TheV I iositive-going-A pulse vproduced across the cathode resistor 1552is simultaneouslytransmitted"to the coupling condenser -1553fand also toacoupling condenser 1559.

However, the Vpulse' transmitted-tothe condenser` 1553 isL blocked at aneonlamp Y1546 fassociatediwith thethird n bistable circuit'includingthe tubes l15,40 and 15,45Y inasi-v muchas the lright `hand-terminal ofthe neon'lamp11546 is f l connected to a positive potentialof thecathodefresistorof' y the Yconductive space tube 15475; Thus,'when thepulseA tran'smittedthr-ough the condenser 155.3 and the preceding.

neon lampshis applied tothe neon lamp V1546, bothelec-`V trodesrof thislamp arev at a positive potential, and the diode1546 does not'breakdown'.` to transmit the pulse to fthercontro'lelectroderofrthe tube1650. n i

' However, @thel positivek pulse suppliedto the coupling f' ;vlcondenser 1559 is transmitted through `a series kof'neon` "1. lamps,including a lampV 1548, tofthe control electrodes -of l aresequentiallyrendered conductiverto transmit the posif`v tive-going pulseprovided by firing the letter shift prime the ligure. shift tube16551VTheneon-tube 1548, which is V associated withthe'j third bistablecircuit including the tubes 1540 and 1545,V has its .right handelectrode Vconf nected to ground through'thel cathoderesistance ofthe,extinguished mark tube 1540and its left handelectrodeA Vconnected togapositive potential on thencathode vresistorY 'of the conductive-spacetube-1545.y This biasing arrange?A 'ment for the lamp 1548, ascontrasted with that provided for the lamp 1546, permits it to ionizeand pass the pulse from the condenser 1559 through the remaining neonlamps to the control electrode of the iigure shift tube 1655, therebyrendering this tube conductive. The flow of current through a cathoderesistor 1656 associated with the figure shift tube 1655 produces apositive potential which, when added to the positive potential acrossthe cathode coupling condenser 1653, is suthcient to elevate thepotential of the cathode of the letter shift tube 1650 to a point thatthis tube is extinguished. 1n addition, the firing of the tube 1655provides a positive potential which is supplied throgh a series resistor1561 to a blocking diode or neon lamp 1552 associated with the controlelectrode of a figure shift drive tube 1500, thereby providing anenabling potential for this tube.

The firing of the tube 1515 also extinguishes the prime tube 1675 toremove the switched bias from the tubes 1650, 1655, 1660, 1665 and 1670,tires the tube 1680, and resets the bistable circuits to spaceconditions, as described above. The completion of this cycle ofoperation of the counting chain also momentarily operates the motormagnet 910 in the transmitter 138 to extinguish the tubes in thecounting chain and the drive tube 1550 and to advance the magnetic film137 a single step during which the third code combination recorded onthe lm 137 is swept past the transducing heads 931-935 to transmit thecode combination representing the character F to the bit storage units.The sensing of the character F transmits positive pulses to the controlelectrodes of the mark tubes 1520, 1540 and 1630 so that these tubes arerendered conductive and the corresponding space tubes 1525, 15415 and1535 are extinguished. Accordingly, the tubes 1520, 1535, 1540, 1630 and1645 are in a conductive condition at this time.

The transmission of the character F following the transmission of afigure shift code is utilized to control the transfer of the followingmessage material to a special recorder (not shown). Therefore, when thecounting chain initiates the cycle of operation immediately followingthe storage of the character F in the bistable circuits, the prime tube1675 is again rendered conductive to provide a switched bias at theterminals 1651, 1661, 1666 and 1671. When the tube 1515 is fired in thiscycle of operation of the counting chain, a positive pulse is againcoupled through the condenser 1551 to the control electrode of theletter shift drive tube 1550, thereby rendering this tube conductive totransmit positive pulses to the condensers 1553 and 1559. However, thesepulses produce no useful function inasmuch as the neon lamp gatingcircuits associated with these paths are not conditioned to transmit apulse to the control electrodes of either of the tubes 1650 or 1655inasmuch as neither a figure shift code nor a letter shift code has beenstored in the bistable circuits.

The firing of the tube 1515 also transmits a positive pulse through acoupling condenser 1563 to the neon tube 1562. As set forth above, theright hand electrode of this blocking diode is connected to a positivepotential through the resistor 1561, and the pulse supplied to thecondenser 1563 is coupled through the diode 1562 and a couplingcondenser 1564 to the control electrode of the gure shift drive tube1560, the control electrode of which is provided with a fixed bias by avoitage divider. Firing the tube 1550 produces a positive-going pulseacross a cathode resistor 1565 that is coupled through a condenser 1566to a series circuit of neon lamps which are selectively strapped to thecathode resistors of the tubes in the binary pairs in accordance withthe mark and space conditionspforming the F code. Therefore,

va pulse is transmitted through this circuit only when the tubes 1520,1535, 1540, 1630 and 1645 are in a conductive condition to represent thecombinational code for the character E This pulse is applied to thecontrol electrode of a figure shift F control tube 1660, the control 10electrode of which is supplied with an enabling bias by the prime tube1675, so as to re the tube 1660. The operation of the tube 1660indicates that a figure shift F code combination has been received bythe transmitting eommutator 214.

The counting chain in the transmitting commutator 214 thereuponcompletes its cycle of operation incident to which all of the spacetubes in the binary pairs are placed in a conductive condition, the marktubes in the binary pairs are extinguished, the prime tube 1675 isextinguished, and the motor magnet 910 in the transmitter 138 ismomentarily rendered conductive so that the tubes 1550, 1550 and1510-1516 are extinguished and the next code combination recorded on themagnetic tape 137, which comprises the first character in a message, isswept past the transducing heads 931-935 to be stored in the bistablecircuits in the transmitting commutator 214.

T he firing of the tube 1660 places a control circuit (not shown) of thetype disclosed in the above identified Fisher et al. application inoperation so that a magnetic recorder (not shown) is conditioned toreceive the following message material reproduced from the magnetic film137 by the transmitter 13S. This control circuit extinguisher, the tube1660 and releases the start relay 1500 so that the contacts 1501 areopened to interrupt the operation of the counting chain in thetransmitting commutator 214 with the iirst character of the messagestored in the bistable circuits in the commutator 214i. When the specialrecorder (not shown) has been conditioned to receive the information,the control circuit associated therewith reoperates the relay 1500 toclose the contacts 1501 so that the transmitting commutator 214 is againconditioned for operation.

When the next pulse is supplied from the multivibrator 1500 to thecontrol electrode of the start tube 1510, this tube is renderedconductive to perform the functions described above. In addition, thefiring of the start tube 1510 transmits a space pulse to a flip-nopcircuit that controls the applications of Baudot coded signals in serialform to the special recorder or through the switching equipment 210, 219to the data receiver 104. When the tube 1510 is fired, a positive-goingpulse is coupled through a condenser 1507 to a neon diode 1505. Theterminal of the diode 1505 connected to the condenser 1507 is providedwith a positive potential near its ionizing potential by a voltagedivider, and its other terminal is connected to ground through aresistor 1574 so that the lamp 1505 is ionized by the pulse supplied bythe condenser 1507. The ionization of the diode 1505 transmits apositive-going pulse over a space signal conductor to a condenser 1771that is connected to the base electrode of a transistor 1770 in theoutput flip-nop circuit. The application of a positive pulse to thetransistor 1770 operates the flip-nop circuit to transmit a space pulserepresenting a start signal.

When the next tube 1511 in the counting chain is rendered conductive, aspace pulse or a mark pulse is transmitted to the flip-flop circuit inaccordance with the marking or spacing condition stored in the iirst bitstorage unit comprising the tubes 1520 and 1525. When the tube 1511fires, a positive-going pulse is coupled to both of a pair of condensers1572 and 1573. Assuming that the mark tube 1520 in the rst bistablecircuit is now conducting, a positive potential is supplied to oneterminal of a neon lamp or gate 1570 through a resistor 1576, and theother terminal of this .neon lamp is connected to ground through aresistor 1575. Accordingly, the application of a pulse to the condenser1572 causes the neon lamp 1570 to pass this positive pulse so that it istransmitted through a coupling condenser 1761 to the base electrode of atransistor 1760 comprising the other of the pair of transistors formingthe lhpdiop circuit. Since the space tube 1525 in the first binary pairis extinguished due to the conductive condition of the mark tube 1520,both sides of a gate means comprising a neon tube 1571 are connected toground,

lili

onevsideA through-the cathode resistor of the tube 1525 andthe othensidethroughthe resistor 1574.. Accord-y ingly, the vpulse transmittedthrough'the coupling condenser 157,3 is not further transmitted to theinput of the transistor'1770f- In a similar manner, the firing of eachyof the tubes'1512, 1513, 1514fand 1515 selectively couples a`positive-going pulse either to the base electrode of-the transistor 1760orV to the base electrode of the transistorv 1770 through one of a pairof neon tube gates in accord ancev withrthe mark or space conditionstored inthe associated bit storage unit. v Y

Following thefiiring of( the tube 1515, the tube 1516 isrired totransmita stopv pulse to the transistor 1760 through acondenser 1623 anda neon lamp 1624 having aVV fixed enablingbias. The firingof the tube1516 again momentarily energizes the motor magnet'9`10 in thetransmitter'138so that'the next item of information stored' onrepresenting a space condition is supplied to the input of theflip-opcircuit. This pulseris transmitted through the coupling condenser17771. to the base-electrode of the transistor 1770. Assuming that thetransistor 1770 is in a conductivezcondition at this time, the positivepulse supplied through the coupling condenser 1771 places the baseoperation of the flip-iop circuit,

coupling condenser 1761 ltransistorV 1760, this. Vpositive-going pulserenders the transistor. 1760 nonconductive `so that the.. voltage drop.

across the resistor 1772.1is terminated.Y .This provides a.A

12 to the hase electrode of the sufHciently-negative bias on'the baseelectrodeof the transistor 177010 place this .transistor in. aconductive state. The' collector. current flow through the conductivetransistor 1770 provides a positive voltage drop across the resistor1766 so that the transistor 1760y is maintained ina cutoff condition.The flow of emittercurrent v inthe transistor 1770 provides a negativepotential across the emitterresistor 1775 which is supplied to theemitter electrode of the buffer transistor1780. The application lof anegative potentialto this emitter electrode together withY the'termination of the conductive condition in the transistor-1760; whichcauses theA base electrode of the transistor 1730 to go to.substantially ground potential, renders the transistor 1780nonconductive. The termination of'collector current flow'in thetransistor v1780 provides a more negative potential `at'the baseelectrode ofthe output drive transistorf1790; The application of a morenegative potential to Vthis baseelectrode places thetransistor 1790 in aconductive condition so that current owsthroughor avoltage drop isyproduced across the resistor1793. Y

Thus, the transistors 1760 and-1770 provide a flip-flop circuit whichhas two stable cond-uctivestates and which is operated between the twostable states only in response l to the application. of. atriggeringpulse Vfrom the mark and space pulse conductorsvofthetransmittingcommutator 214.. Y The transistors 1760 and c1770control the conductive or nonconductive stateof the outputdrivetransistor 1790 so that mark and Vspacepulse informa electrode of thetransistor 1770 at apotentialvthat is POS tion istransmitted in serial fo-rin to either the special tive'with respect tothe emitter electrodesoV thatY conduc .tion in the transistor `177 0 is terminated. Theinterruption'.

of current flow in the collector circuit of the transistor 1770 reducesthe potential drop across a resistor- 17566` in a voltage divider thatalsoincludes a pair'of resistances This places a Ymore negativepotential f 1774, to maintain a more positive potential on the base.electrode of the transistor 1770. This potential holds the itransistor-1770 in a-nonconductive condition following bination isreproduced by the transmitter. 13S and storedv r`in theybistable'Yt/:ircuits inthe transmitting commutator thedissipationofthetriggering impulse suppliedto the condenser. 1771.

" The termination of conduction through theftransistor 1770 reduces theVpotential drop across anemitter resistor. Y 177550 that the potentialsupplied to the emitter electrodel of a buffer transistor. 1780 becomesmore positive. Further; when the transistor 1760 is renderedzconductive,the

flowof emitter current in the transistor 1760 causes the 'b aseelectrode of thebuier transistor 1730 to drop toY a potential that isnegative 'with respectV toits emitter;

Thus, the emitter electrode of' the buffer transistor1-1780 A bitstorage, units in the transmitting commutator 214, the

conducts rto carry the combined collector and base curv rentsof thetransistor 1760 as Vwell as the collector current'of the transistor1780. This currentl flow provides a, negative potential drop across theresistor 1775 to aid in maintaining the ltransistor v1770 inY a cutoffcondition. Y

' 1545 remaining'in'a conductivecondition;

The flow of current through.a'collectorresistor Y1781'of the conductingbuffer transistor1780 providesa more posif tivepotential-on the, baseelectrode ofoutput drive tran- Y sistor1790 so that; this transistor iscutoff,` the emitterv electrode thereof'being provided with a smallxednega-v representa space Apulse or signal.

. Assumingthahamarkpulse is transmittedthrough ther"` recorderorVthrough. theswitching equipment 218ir 219 to the datal receiver 104. s l

As indicated above, the firing of the tubey 1660 controls circuits rforrouting the. coded data entries supplied at the output of thetransistor1790 to the-special recorder.v Accordingly, the transmittingcommutator 214 and the trans-Y o nfthe.magneticfilmV 137 to the specialrecorder. When the-transmission vof information to the'specialV recorderis to be terminated, Vajiig'me shift v.G code combina-tionv is storedvon the magneticlm1'37. When this code corn- 214, thev .commutator 214detects this code combination fandinterrupts the transmission ofinformation to the,

.special recorder. Y y

Vlv/iorez specifically,'in thecyclefof yoperation following the, storageof the-.figure `shift*code combination in the figure shift tube 1655 isrendered conductive, as described above, so thatan'enablingbiasis-provided at its cathode resistor 165.6 for biasingtheblocking .diode1562 to a.

point near itsionizing potential.Y Thereafter, the transs mittingcommutator 214 is cleared, andv theV transmitter 60 .138 transmits acodecombination representinglthe charac-y ter` VGf to the :transmittingcommutator 214 which is 1 stored Vin the bistable` circuits byrenderingthe'mark tubes 1530, 1630`and'1640 conductive, the space tubesv1525 and,

ing'thejstorage of this information in the'tra'nsmittin'g7comm'utator214,the tube V15157isrendered conductive to Atransmit'a:pulse through thecoupling condensers V1563 and 1564v andthe blockingYdiode 1562 to-the control electrode of the'ffigure es'hift drive tube1156011 This; renders this tbe conductive so that a positive pulse istransmitted through alcondenser 1567 and a plurality of seriesconelement1793in'the output signal line is interrupted to Y transmitted only -overthis` series circuit arrangements be- In he cycle of operation ofthecounting chain follow cause the conductive tubes 1525, 1536, 1545,163) and 1655i? enable all the diode gates in only this path. Thispositive pulse supplied to the coupling condenser 1566 from the cathoderesistor 1565 of the tube 1564i is not transmitted to the controlelectrode of the figure shift F control tube 166) inasmuch as all of thediode gates connected in series therewith are not properly biased forconduction.

The control tube 1665 is provided with an enabling bias at the terminal1666 by the conductive prime tube 1675, and the tube 1675 is renderedconductive by the pulse from the decoding circuit to provide a controlsignal that renders the marker control and register decoder 230, 240responsive to the following codes supplied by the commutator 214 and thetransmit-ter 138. The firing of the tube 1665 also terminates thetransfer of information from the drive transistor 179) to the specialrecorder. Following the firing of the tube 1665, the counting chain inthe transmitting commutator 214 completes its cycle of operation toperform the functions described above and, in momentarily operating themotor magnet 911B,

ctuates the transmitter 138 to store the first of a series of codesrepresenting the designation of the data receiver 1194 that is toreceive the following message material stored on the magnetic film 137.This first code or one digit thereof is now stored in the five bistablecircuits in the transmitting commutator 214 and is supplied from thecathodes of the tubes 1520, 1530, 154i), 163i) and 164i? over aplurality of conductors to the marker control and register decoder 230,240. The tube 1665 is extinguished and the start relay 1560 is releasedso that additional inform-ation is not reproduced by the transmitter138.

The marker control and register decoder 239, 24) translates the firstdigit supplied by the tarnsmitting cornmutator 214 and then operates thestart relay 151B@ so that the next switching code is reproduced from themagnetic film 137 and transferred through the transmitting cornmutator214 to the circuit 230, 246. The marker control and register decoder230, 240 operates in this manner until all of the necessary switchdirecting information has been received and the switching equipment 218,219 is operated to connect the output of the drive transistor 1790 tothe correct data receiver 104. At this time, the marker control andregister decoder 23), 244) is effectively disconnected from hetransmitting commutator 214, and the start relay 1500 is again operatedso that the message material stored on the magnetic lm 137 is reproducedby the transmitter 138, stored in the transmitting commutator 214, andtransmitted by the commutator 214 to the flip-flop circuit including thetransistors 1760 and 1770. The mark and space information provided bythe drive transistor 1796 controlled by the flipflop circuit istransmitted through the switching equipment 218, 219 to the selecteddata receiver 104. In the event that the material previously stored inthe special recorder is also to be transmitted to the selected datareceiver 104the figure shift F code combination is inserted in themessage material and controls the transmitting commutator 214 in themanner described above so that the tube 1660 is rendered conductive. The firing of the tube 1660 at this time operates the related controlcircuit so that the information previously stored in the specialrecorder is transmitted to the selected data receiver 164.

A figure shift H combination is stored as the last entry on the magneticfilm 137 to indicate the end of the message. When this information isreproduced from the magnetic film 137 and stored in the transmittingcommutator 214 this commutator decodes the figure shift H combination torestore the transmitting commutator 214 to a normal condition. Morespecifically, the transmission of the figure shift code combination fromthe transmitter 138 to the commutator 214 tires lthe tube 1655, and thefollowing storage of the H code combination in the bistable circuits inthe transmitting commutator 214 places the tubes 1525, 1535, 154?, 1635and 1640 in a conductive condition. When the counting chain in thetransmitting commutator 214 advances through its next cycle ofoperation, the figure shift drive tube 156i) is fired to supply apositive pulse to a coupling condsenser 1563 and also to the couplingcondensers 1566 and 1567. The pulses supplied to the condensers 1566 and1567 perform no useful function inasmuch as transmission of these pulsesto the control electrodes of the tubes 166i) and 1665 is blocked by theseries arrangement of gates, at least some of which are not enableddiodes. However, the diodes connected in series with the couplingcondenser 1568 are properly conditioned by the selective operation ofthe bit storage units, and a positive pulse is coupled to the controlelectrode of the tube 1670 to render this tube conductive. The firing ofthe tube 1670 restores the data handling system including thetransmitting commutator 214 to a normal condition in the mannerdescribed in detail in the Fisher et al. application.

Although the data handling system has been described in conjunction withthe details 0f an automatic telegraph system, the circuits andoperational techniques embodied therein are capable of generalapplication. Accordingly, it should be understood that many othermodifications and embodiments can be devised by those skilled in the artthat will fall within the spirit and scope yof the principles of thisinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

l. A data transmitting apparatus for use with plural bit code signalscomprising a plurality of electronic means, means for operating saidelectronic means in accordance with the code bits of a signal to betransmitted, a pair of signal conductors, a pair of gate circuitsconnecting each of said electronic means to both of said conductors, andpulse generating means for selectively supplying signals representingthe code bits stored in said electronic means to one or the other ofsaid pair of conductors through a selected one of each of said pairs ofgate circuits.

2. A data transmitting apparatus for use with plural bit code signalscomprising a plurality of pairs of electronic means, means forselectively rendering one electronic means in each of said pairs ofelectronic means conductive in accordance with the bits of a code signalto be transmitted, a pair of signal conductors, individual first gatecircuits separately controlled by a given one of said electronic meansin each of said pairs of electronic means and connected to one of saidconductors, individual second gate circuits separately controlled by theother one of the electronic means in each of said pairs of electronicmeans and connected to the other of said conductors, and means forsupplying signals to Said first and second gate circuits to providesignals on said conductors in accordance with the bits of the codesignal to be transmitted.

3. The apparatus set forth in claim 2 including a switching circuithaving two stable states connected to said two signal conductors forsupplying output signals to a single signaling line in accordance withthe signals applied to said two signal conductors.

4. The apparatus set forth in claim 2 in which the said means forsupplying signals includes a counting means having a plurality ofseparate elements each separately connected to the individual first andsecond gate circuits associated with each separate one of said pairs ofelectronic means.

5. A data transmitting apparatus controlled -by a magnetic memberadapted to`store plural bit code signals comprising a plurality of pairsof discharge devices connected as switches having two stable states, aplurality of transducing heads disposed adjacent said member andindividually connected to one of the discharge devices in each of saidpairs to operate said pairs of dischargedevicesto stable states inaccordancewith f' the bits of 'a code'signal. to be transmitted, a gatecir-. i

cuit individual to each of said pairs and controlled'ithereby, outputsignaling .means connected to all of said gate circuits, a countingmeansconnected to said gate cirq cuits, means for. operating said. countingmeans.. through a fixedV cycle for selectively. supplyingsignals to`said output signalingmeans under the control of saidgate f YcircuitsAand in accordance .with the code signal to be VYl() transmitted,Y andlmeans operated under the control Yof Said countingmeans forperiodicallyadvancing said mem- Yber to supply code signals to be transmitted tosaid pairs.

of discharge-devices.v

6. The data transmitting apparatus set of operation.

`7. The data transmitting apparatus set forth in. claim a 5 includingAmeans in said counting means Yfvorrsupplying Vl2. The vsystem set.forth inyclaim l1 in which said cordance with the'bits of plural bitcode, av plurality of f gate circuits connectedto and controlled by eachof said I Y devices, first control means, first circuit` meansconnecting one of the gate circuits connected `to each of said devicesto saidfrirst control means, second control means, secondy circuit meansconnecting another of the gate circuits con' forth in claim 5V includingymeans. operated by saidj'counting means for` operating all Aof said.pairs to. a predetermined vone .of said stable states incident to eachof.' saidA xed cycles'y predetermined signalsito said .outputsignaling.means in.

cidentgto each ofsaid xed cyclesof operation.

8. A. data transmitting system comprising a plurality.

of controlled conductionl devices selectively vopelablerto rprovide apattern of conductive conditions .representing the .bits of 'plural bitcode signal, acounting means Vop- 1 erable through a fixed cycle, meansincluding said plurality of controlled `conductionfdeviccs and saidcounting means for supplying outputjsignals in. accordance.withY.v

said bits, control means, a decoding network connecting said' pluralityof, controlled conductionl devices. to said control means, Vand meanscontrolled by said counting meansrfor supplying an'opierating signal tosaid vdecoding ynetwork incident to eachy cycle of operation of said. Y

counting'means to operatesaid controlmeans only Ywhen'` said plurality.of controlled conduction .devices `provide @predetermined rattern.'

9'. A data handling system prising a. plurality of switch pairs ofelectronic. devices having` two. stable states, means. including f meansfor advancing said, medium for transmitting code signals to saidsvvitvchpairsi to establishdifferent patterns of stable statesin .accordance.with Vthe bits ofsaid code signals, .i

countingrmeans operable through successive cycles of operation,signaling means connected to said switch pairs.V

and .including said' counting means for supplying A output signalsinaccordance with code signals, decoding means,v

connected to said switchI pairs, control means connected tosaid decodingmeans, andmeans controlled'by said counting',V means for operating rsaid decodingmeans incident to,r eachrofvsaid *cycles,of operation, saidcontrol lm'eans being;v actuated by. said decoding means whena- Ypredetermined pattern .is provided infsaid .Switch pairs."

@ltrolled'conduction meansgin ,said chain suppliesjy asignal.

ftofeach' of said iirstpluralityoff.gatej circuits, saidY gate.

circuits controlling the'selectiveapplication of .signals to. Y Y saidsignaling channel in accordance with the pattern pro- 11. In-a :datahandlingY system,'; plurality of con'-V i' l0; The'systeni set forthinlclaim Y9 in which said decodingmeans Vincludes a-pluralityof gatecircuits connected tofand controlled by said switch pairs and in whichsaid means for "operating said decoding4 means includesy a, controlledconduction devicer'controlledby said count.

ing means.

trolled conductiondevices selectivelygoperable to diler-` ent patternsof conductiveand. nonconductiveconditionsV in accordance'with theV bitsiofV a plural Vbit code, la .plu-

rality or". grate circuitsrc)nnectedV toeach ofsaid devices,V`

a plur-ality'of :controlV means,fcircuitfmeansV connecting Y Vdiierentlgroups ofV Vsaid gate circuits vin se'riesv and 'to ,Y'ditferent'onesrof said control means, each of said. groups Y includingone i gatecircuit 'connected'.to.. Yeach-o f-gsaidY Y devices,ands'ignalingmeans for simultaneously supply- Y..

nected to each of said devices to said second control means, iirstsignaling means for supplying a signal to said lirstcircuitfmeans tooperateY said Yiirst control means only` when, said devices provide apredetermined pattern,- andl second signaling means Vcontrolled by said`lirst control measn for supplying a signal'to said second circuit meansfor operating said second control means. 14. The systemset forth inclaim v13finvwhichY saidirst andfsecondsignaling means includealc'ounting means for supplyingfsaid signals yto said rst and secondcircuit means at time spaced intervals.

l5. A.Y data transmitting apparatus comprising a pluv'ralityof pairs' ofdischarge tubes, means connecting each of'said pairs of tubes to form aswitch'pair .having two,y

stable states in which only one or Vthe other of the vtubes isconductive, means for selectively operating said .pairs ofdischargetubesto selected patterns ofstable states in.v

accordance withthe bitsof a plural bit code signal, a mark signal,conductor, a spaceY signal'conductor, a lirst plurality of gate circuitseach connecting one of said tubes YinvsaidV pairs to '.thernarkconductor, a second plurality of gatecircuitseach connecting 'thejothertube insaid pairs to the space Qconductonia counting'lchain' including.

Y Vaf plurality of discharge devices each individuallyconfor Yuse'withia sensible fi medium adaptedV to store plural` bitcodepsignals com;Y

oneof said` mark'andspace.conductors as each of. saidV charge devicesVtherein so that afpulseis transmitted to v discharge devices Vis"iiredlunder the control of the two i Vgate circuitsconnected.tojthereddischarge deviceranckl.V

vingaccordance'withthestable stateoffthe pair of tubes connected tothese twov gate circuits.

16. A. data transmittingapparatuscomprising. a. pluf f ralityorcontrolled conduction devices..Y selectively operable to patterns ofVconductive Vvand lnonconductiveV conditions in accordance 'with the bitsof plural-bit code, a rst v70 I y'ra'lityig of pairsV of; controlledconduction ".de'vices,. means connecting each'of said pairsofdevices'to'forma bistable ing signals'to` all of-'saiddiierentgroupsofeconnected ,j

V.gate circuits: to nperateV a selected one .of said control meansinaccordance with thejpattcrnprovided@by said.

controlled conduction devices@ e plurality of ga'te'circuits eachconnectedl to and controlled by one of said devices, asignaling .channelconnectedrto said gate circuits,a counting chainfincluding.acontrolledVVconduction means lcoupled to eachrof said first plurality of gatecircuits, means for operating said countingchain throughfa cycleofoperation so thateachof theconvided by .said plurality of controlledconductive devices, avsecond pluralitylof gate circuitseach connected.to and.

controlledby one: of ,saidv plurality of' controlled. conducf'vjtiondevices, aV control means, means. connecting saidsec.- ond*`plurality' of gate :circuits to .said control means, and A rneans'for'supplying'a signal to saidsecond plurality. of Y gate Vcircuits to'operatesaidcontrol'meansA only when f saidsplurality of controlledvconduction a-predetermined pattern.Y

devices provides 17. A Vdata transmitting :circuit having twostablestates Yin only onero'r the other'otjthedevicesjsrconductive, nieansfforselect1vely1 operating Ysaid' bistable circuitsimto selectedpatterns ofi g'rapparatus': comprising "a plul? stable states in accordance withthe bits of a plural bit code, a mark signal conductor, a space signalconductor, a plurality of first gate circuits each connecting one of thedevices in one of said bistable circuits to the mark conductor, a secondplurality of gate circuits each connecting the other device in one ofsaid bistable circuits to the space conductor, a counting meansincluding a plurality of controlled conduction means each individuallyconnected to the two gate circuits connected to each of the bistablecircuits, means for operating said counting means to sequentiallyoperate the controlled conduction means therein so that a pulse istransmitted to one of said mark and space conductors as each of saidcontrolled conduction means is operated under the control of the twogate circuits connected to the operated controlled conduction means andin accordance with the stable state of the bistable circuit connected tothese two gate circuits, a plurality of third gate circuits eachconnected to and selectively controlled by one of said bistablecircuits, control means, circuit means connecting said third gatecircuits to said control means, and means controlled by said countingmeans for applying a signal to said circuit means to operate saidcontrol means only when a predetermined pattern is provided by saidbistable circuits.

References Cited in the file of this patent UNITED STATES PATENTS2,906,999 Wright Sept. 29, 1959 2,948,882 Fisher Aug. 9, 1960 2,976,347Fisher et al Mar. 2l, 1961

1. A DATA TRANSMITTING APPARATUS FOR USE WITH PLURAL BIT CODE SIGNALSCOMPRISING A PLURALITY OF ELECTRONIC MEANS, MEANS FOR OPERATING SAIDELECTRONIC MEANS IN ACCORDANCE WITH THE CODE BITS OF A SIGNAL TO BETRANSMITTED, A PAIR OF SIGNAL CONDUCTORS, A PAIR OF GATE CIRCUITSCONNECTING EACH OF SAID ELECTRONIC MEANS TO BOTH OF SAID CONDUCTORS, ANDPULSE GENERATING MEANS FOR SELECTIVELY SUPPLYING SIGNALS REPRESENTINGTHE CODE BITS STORED IN SAID ELECTRONIC MEANS